Quartz glass melting.

Precise monitoring of viscosity during the melting process is crucial for quality assurance in quartz glass production. In this project, a Sensor Technology TorqSense torque transducer (SGR541) was used to enable real-time conclusions to be drawn about material homogeneity, purity and the progress of material bonding.

In modern glass technology, precise control of melting conditions is of fundamental importance: the viscosity of a melt in particular has a decisive influence on its further processing, quality and homogeneity. In the laboratory, viscosities are often determined using rotational viscometers: a spindle is rotated at a constant speed in the sample, the required torque is measured and the viscous resistance – i.e. the viscosity – is determined.

In their customer's project, this concerns the melting of quartz glass. Viscosity is not only a measure of fluidity but also allows conclusions to be drawn about the internal state of the melt – for example, cavities (air bubbles) or incomplete material bonding. Focusing on precision glass components to improve the manufacturing process for quartz glass in terms of quality and process reliability. The challenge was that the glass is first melted at high temperatures and then has to reach a defined viscosity zone for further processing. Only in this range can it be guaranteed that the melt is homogeneous (no air bubbles), the connection or fusion of different material batches has taken place completely, the transition to the shaping or quenching/pre-forming process starts reliably.

The objective was to reliably monitor the viscosity of the quartz glass melt in order to detect deviations in the melting process at an early stage and to establish process-reliable feedback for control and quality assurance.

The viscosity of molten glass plays a key role in processing, as it determines the flowability and thus the moulding behaviour, bubble removal, degassing and homogenisation. In the case of quartz glass, the conditions are particularly demanding with: high temperatures and viscosities having a strong influence on the viscosity curve.

The TorqSense SGR541 was chosen because of its great robustness against extreme process conditions (temperatures, thermal shocks, possible vibrations) in the melting range of quartz glass with separate sensor unit and electronics. Calibration was performed using reference samples or model melts in order to map the torque ↔ viscosity relationship in detail in the specific process setup.

The sensor was integrated into the process—typically between the motor/agitator (or melt mixing system) and the impeller (or melt stirrer)—and connected to the process control system in real time. Since torque transducers can be sensitive to lateral forces, double bearings should be used to avoid transverse forces.

The relevant target values for viscosity were defined together with the customer: e.g., a range from x to y Pa·s at temperature T, at which the melt is considered homogeneous and no bubbles are mobile.

Reference curves were created using laboratory or pilot melts with known compositions and viscosity values. This allowed the sensor output to be mapped to absolute or relative viscosity (see Basics: “Torque ↔ Viscosity” at constant speed conditions). The sensor continuously provided torque data from which the viscosity was derived. Trend analysis enabled early detection of deviations – for example, if the viscosity did not fall within the target range, which could indicate trapped bubbles or incomplete mixing of the material batches.

As soon as the measured viscosity deviated from the target curve, measures were taken immediately: adjustment of the temperature, extension of the stirring time, addition of degassing (refining), or even return of the batch for reprocessing.

The introduction of monitoring using SGR541 had the following positive effects: The melt could be continuously monitored for homogeneity and freedom from bubbles. Deviations were detected early and corrected. The data obtained (torque/viscosity curves) provided valuable insights into the behaviour of the quartz glass melt, enabling future process optimizations.

This method is also used successfully in other applications—e.g., plaster mixtures, coal slurries, and liquids containing magnetic particles—where conventional viscometers fail and viscosity monitoring is required. In industries such as cosmetics and pharmaceuticals—e.g., in the manufacture of shampoos or medical solutions—it is also important to monitor viscosity during mixing. This allows you to determine when the process is complete and the desired consistency has been achieved.

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@Sevcon #PAuto #viscosity TorqueSense #Transport

Breakthrough in torque and angle measurement.

The SGR523, a state-of-the-art digital rotary torque sensor equipped with an integrated incremental angle encoder has been introduced by Sensor Technology. This innovative addition to the TorqSense SGR series sets a new benchmark for precision in torque and angular position monitoring across various industrial applications. The SGR523 employs non-contact strain gauge technology, eliminating the need for traditional slip rings and enhancing reliability. Its high-resolution angle encoder delivers up to 10,000 pulses per revolution with a remarkable resolution of 0.009°, making it ideal for applications requiring meticulous torque-angle analysis, such as mechanical testing, automated assembly, and process control. 

Key Features:

• 
  Torque measurement range from 175 mNm to 20 Nm
• Accuracy of ±0.1%
• High mechanical overload capacity of 400%
• Overrange reading capability of 250%
• High digital sample rate of 4000 samples per second
• Digital outputs: RS232 and USB (standard); CANbus and Ethernet (optional)
• Bi-directional angle and rotation count
• Speed measurement up to 9000 RPM
• Compatible with TorqView Advanced Torque Monitoring Software
• Lifetime warranty

The SGR523's advanced capabilities enable engineers to detect mechanical anomalies, such as rotational stiction or thread damage, by analysing torque versus angle plots. This dual-parameter monitoring is crucial for quality assurance in manufacturing processes, including bottle cap tightening and bolt fastening.

The sensor's ability to monitor torque at specific shaft angles aids also in identifying potential issues in process control applications, thereby reducing production wastage. Its high-resolution angle measurement also facilitates precise motion control, allowing for better management of inertia in motion platforms and improved safety in automated machinery.

The SGR523's design simplifies system architecture by combining torque and angle measurement into a single unit, reducing component count and enhancing system reliability. Its robust construction and advanced diagnostics, including Built-In Test (BIT) self-diagnostics and shaft temperature monitoring, ensure consistent performance even in demanding environments.

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@sensortech #PAuto

Torque Sensors for fastening.

The latest advancement in torque sensing technology – the SGR525/526 Torque Sensors has been launched by Sensor Technology. Designed for precision and versatility, these state-of-the-art sensors feature square shaft ends, making them ideal for a wide range of industrial and laboratory applications.

With decades of expertise in torque measurement, Sensor Technology has engineered the SGR525/526 series to provide exceptional accuracy, reliability, and ease of use. The square drive design allows for seamless integration into power tools, test rigs, industrial machinery and precision fastening applications, ensuring superior torque measurement without the need for additional adapters or modifications.

“We are thrilled to introduce the SGR525/526 torque sensors, which respond to industry demand for more adaptable and robust torque measurement solutions,” said Mark Ingham, Sales Director at Sensor Technology Ltd. “By incorporating square shaft ends, we are offering our customers a practical and efficient way to enhance their torque monitoring capabilities.”

Key Features of the SGR525/526 Torque Sensors:

• Square Shaft Ends – Allowing direct compatibility with precision fastening applications.
• High Precision Measurement – Providing reliable and accurate real-time data.
• Robust and Durable Design – Built for industrial environments and high-load conditions.
• Easy Installation & Integration – Compatible with standard torque measurement setups.
• Wireless & Digital Output Options – Enabling enhanced data acquisition and analysis.

The SGR525/526 torque sensors cater to industries such as automotive, aerospace, manufacturing, and research & development, where precision torque monitoring is critical for performance and safety.

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@sensortech #PAuto #Maintenance

Replacing DIY test rigs!

RTEC Engineering Ltd is on a mission to redefine accuracy standards for dynamometers amid the growing global interest in enhancing engine efficiency and performance. Their cutting-edge technology is grounded in a novel torque measuring technology.

Rob Langton, the Managing Director of RTEC Engineering Ltd and an engineering metrologist with over two decades of experience, sheds light on their innovative approach: "Our sub-division, RTEC Powertrain, is actively engaged in collaborative projects with B2B partners, concentrating on metrology solutions for the automotive industry, including ECM (engine control module) calibration and diagnostics."

Facing the challenge of obtaining a detailed performance profile for a specific engine within a constrained capital budget, Langton took matters into his own hands. Drawing on his extensive engineering expertise, he embarked on designing and manufacturing a dynamometer that replicates the accuracy and reliability of OEM or lab-grade systems but at a more accessible cost for small to medium-sized enterprises.

Striving to surpass the limitations of load cells and RPM sensors commonly found in traditional dynamometers, Langton turned to advanced technology. After researching specialised literature, he discovered Sensor Technology and their non-contact TorqSense transducer.

Engineers from Sensor Technology assessed Langton's requirements and recommended the SGR510/520 series TorqSense. This innovative transducer employs a full four-element strain gauge bridge. A rotor-mounted ultra-miniature microcontroller, powered by a non-contact inductive coil, measures strain values and transmits them digitally to the stator, providing high-precision torque measurements.

Langton highlights the benefits: "The inductive coils eliminate the need for wires with slip ring connections to the shaft, offering the ease of use we desire." 

He underscores TorqSense's remarkable 250% overrange capacity, enabling accurate measurement of sudden load spikes. Additionally, its immunity to noise and signal corruption, common in slip ring setups, along with a 4000/sec sampling rate, aligns seamlessly with their resolution requirements. With Sensor Technology's assistance, RTEC swiftly developed an ideal solution for manufacturing a high-performance dynamometer aligned with their design specifications. Recognising the potential broader applications, Langton explored the market's needs, leading to a realisation of a gap that RTEC aims to fill.

While calibration of elements like the load cell is typically carried out by UKAS accredited laboratories in larger organisations, RTEC identified a market gap for smaller entities. They are now working on a scalable, modular dynamometer design with TorqSense at its core. TorqSense's factory calibration to NPL standards and its self-contained nature, combined with a plug-and-play design, simplify exchanges during calibration, minimising downtime. RTEC's future projects include crafting bespoke test rigs tailored to users' exact specifications and retrofitting TorqSense into existing dynamometers and test rigs, spanning precision instrument drives to heavy vehicle power trains.

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@sensortech #PAuto #Maintenance

Revolutionising torque measurement.

The TorqSense SGR521 transducer from Sensor Teachnology, is a significant enhancement in their innovative TorqSense rotary strain gauge series. In addition to standard digital outputs such as RS232 and USB, the TorqSense SGR521 now features an optional Ethernet output, providing users with enhanced connectivity and data transfer capabilities. This allows for seamless integration with various systems and facilitates real-time monitoring and analysis.

The SGR series transducer utilises non-contact technology, effectively eliminating the common drawbacks associated with slip rings, and employs modern strain gauge signal conditioning techniques to deliver a remarkable torque measuring solution. With a broad array of capabilities, the SGR521 transducer offers:

• Torque Measurement Ranges: Available from 175 mNm to 13,000 Nm
• High Accuracy: ±0.1%, ensuring reliable measurements
• Mechanical Overload Capability: An impressive 400% overload capacity
• Overrange Reading: Up to 250%
• Rapid Sampling Rate: A high digital sample rate of 4000 samples per second

The Ethernet output supports high-speed data transfer, enabling smooth integration into networked systems and enhancing remote monitoring capabilities. This empowers users to operate with greater efficiency and effectiveness. This innovative connectivity solution is poised to transform how torque measurements are captured, analysed, and utilised across diverse applications.

The TorqSense SGR521 transducer connects effortlessly to a Local Area Network (LAN), allowing for seamless integration with existing structured cabling and infrastructure. This capability makes the transducer instantly accessible to any device on the network, significantly enhancing operational efficiency and data accessibility. Users can access the transducer from any location within the premises where structured cabling is present or extend their reach through wireless networking technologies. Furthermore, if the network is connected to the internet or gateways and VPNs are implemented, the accessibility of the transducers can be extended indefinitely. This means that monitoring and control can occur from virtually anywhere in the world, providing unparalleled flexibility for users.

Historically, our transducers relied on technologies that allowed only a single device to connect and consume data at a time. With the introduction of Ethernet connectivity, multiple devices can now access the transducer simultaneously, allowing for collaborative data monitoring and analysis. By implementing standard Internet Protocols, any network- or internet-connected device—from smartphones and tablets to PCs, laptops, and even Arduino or Raspberry Pi development systems—can easily access the transducer. Communication occurs primarily through low-overhead UDP packet transmissions, ensuring efficient data exchange. This is complemented by an embedded web server, enhancing the user experience by facilitating easy access to data and configuration settings.

To maximise these advancements, our TorqView Advanced Torque Monitoring Software has been updated to support network functionality. This integration streamlines data visualisation and reporting, empowering users with the tools they need to harness the full potential of our torque measurement systems.

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@sensortech #PAuto #Ethernet

Low torque high band width.

A new benchmark performance standards for optical rotary torque transducers has been set by Sensor Technology, The digital ORT 230/240 series is ideal for applications when the demand is for low torque and/or high bandwidth, providing precise, dynamic measurement of rotary and static torque from 10mNm up to 100Nm and for bandwidths of up to 50kHz.

The ORT 230/240 devices benefit from electronics that deliver significant gains in resolution, frequency response, reduced sensor current consumption and faster digital data throughput.

The high speed capability comes from an inherently low inertia, since the electronics are not fixed to the shaft, while non-contact operation ensures a long and reliable life (backed up by Sensor Technology’s lifetime warranty) with high accuracy. The optical operating principle also ensures excellent noise immunity.

TorqSense ORT 230 series sensors provide fixed voltage or current analogue outputs – one for torque and one for either speed or power. The TorqSense ORT 240 provides two user selectable voltage or current analogue outputs – one for torque and the other for either speed, power or peak torque – plus digital outputs including RS232, CANbus and USB for interfacing with modern instrumentation and laptops. The ORT 240 enables users to connect up to 10 transducers via USB, and transducer configuration software for making changes to transducer variables.

Features of both devices include self-diagnostics to report if the transducer’s torque, speed ratings or calibration date have been exceeded, while inbuilt sensors monitor shaft temperature for better compensation and accuracy. The device also offers a simple ‘sensor status’ output.

Complementing these products is Sensor Technology’s TorqView software, providing an easy-to-use advanced torque monitoring package for Windows PCs to assist with data display and recording. It offers real time chart plotting, and is compatible with both Matlab and Excel. Further, LabVIEW VIs are available for users to design their own process control applications, and DLLs are available for users who wish to write their own custom software.

These sensors are an important extension to the Sensor Technology torque monitoring range, and offer an alternative solution when low torque or bandwidth requirements preclude the use of the TorqSense range.

Optical rotary torque sensors use a pair of gratings attached a short distance apart on a strain-sensitive shaft to modulate a light source. As torque is applied to the shaft, a slight twist results which changes the alignment of the gratings and thus varies the light transmitted through to a detector. The use of this technique results in a transducer which is able to detect torque bi-directionally, and which has a fast mechanical and electrical response, low inertia and complete freedom from brushes or complex electronics.

The absence of brush gear allows high-speed operation with a continuous rating up to 30,000rpm standard. Further increases in rpm are available depending upon shaft size. The torque shaft is of low compliance ½° maximum torsion deflection on the smaller transducers and ¼° maximum on the larger transducers at full-scale deflection. Any full scale torque can be specified within the range 10mNm to 100Nm.

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@sensortech #PAuto

Torque in medicine.

Medical experts and sports scientists are becoming increasingly reliant on engineers as their disciplines become more and more technical. Mark Ingham looks at some of the projects his company, Sensor Technology, has helped behind the scenes.

Mark Ingham

Like most rugby players I took my knees for granted until the day a twisting fall resulted in a torn anterior cruciate ligament. Fortunately, these days it can be fixed with surgery and nine months of physiotherapy, but I took some comfort in the fact that Sensor Technology has contributed – modestly – to the medical knowledge of this crucial joint. With the pending Olympics fuelling increased participation in sport, military personnel returning from active service with knee problems and the wear on tear on joints as people live longer the need for new knowledge is growing.

One research programme used a Sensor Technology TorqSense industrial sensor to analyse the performance of implanted replacement knee joints. To do this Sensor Technology helped develop a rig centred on a 100Nm TorqSense transducer with an extended through-shaft supporting crank arms on both ends.

The researchers very carefully align the axis of the TorqSense with the patient's knee and attach the ankle to the end of one crank. They can then use the other crank to move the knee without the patient having to put in any muscular effort, thus isolating the joint. Data collected from the TorqSense during a test sequence builds up a profile of the knee's performance.

TorqSense is based on a full four-element strain gauge bridge design, the transducers have the ability to accurately measure and record sudden spikes in torque load. This ability is becoming increasingly important in automated machinery, integrated systems, test rigs and continuously monitored plant.

TorqSense measures the torque 4000 time per second and uses high performance signal conditioning to provide a corruption-free, high bandwidth torque monitoring solution. This is further enhanced by 250% overrange and 400% overload capabilities, elimination of side and end load errors and real time temperature compensation. The non-contact signal transmission means the sensor exerts no load on the shaft it is monitoring, while maintenance-heavy slip rings have been designed out.

Drug protection.
Errors in drug delivery are being reduced year-on-year in all branches of medicine, due to advances in infusion and monitoring technologies. Most medical pumps are driven by stepper motors, which can be tested by driving them against a DC motor acting as a brake. In one programme we were involved with a TorqSense was mounted between the two motors to record the instantaneous shaft torque during test sequences. These data were then analysed and a model of the motor’s characteristics built up.

The alternative would be to use a very expensive dynamometer, which would also be slower to set up because it would need hardwiring instead of a radio link. Another drug protection related project was based on the observation that when using diagnostic fluids on ill or nervous patients, hospital staff are likely to be feeling the stress and will not take kindly to bottle tops that prove difficult to open. However, they will want the tops to feel secure enough that they can be confident of the fluid's sterility. Thus tightening bottle caps in pharmaceutical plants is a precision operation To this end Sensor Technology has helped develop specialist capping machines, which not only tighten bottle caps within precisely defined tolerance but also log every detail of every bottle. The machines are essentially simple: filled bottles are presented to a torque head, which quickly screws on a cap to a target torque.

Wireless torque sensor

However a batch size is typically 10,000 bottles, and they will have to be capped at say one per second. Every cap will have to hit target tightness, with the measurement logged for traceability. Sterility will be paramount, so the machine will probably operate in a high vacuum chamber to ensure that no bacteria or other contaminants are present. TorqSense met all criteria for this application, it being simple, robustness, high speed and wireless. Basically TorqSense could be used 'as is'; with a suitable mounting arrangements. Similarly, the associated software was ready to go after a bit of calibration and the addition of some bespoke front end graphics.

The software was required to do two things: run the torque up to 10kgcm within tolerances of 10 percent, and record the actual value achieved. This secures the cap to the bottle at a level of tightness that will ensure security and sterility, yet is at a level that can be opened relatively easily by an adult. The logged values are saved to a hard drive to provide a permanent record for traceability.

Diagnostic fluids are distributed widely, typically to every hospital in the country plus many overseas. But they may be stored for months before use. Tracing each bottle's origin would be practically impossible without full records being automatically produced and saved to a central location.

Sensor Technology helped provide a solution to this complex but critical problem using an out of the box technology.

Wheelchair reliability.
In a more conventional engineering environment a TorqSense is helping ensure the reliability of powered wheelchairs, having been incorporated into a dynamometer rolling road built by PG Drives in Dorset. The rolling road measures the torque between the motor under test and the inertia network it is driving, which is simulated by selective use of both passive and active loads. The TorqSense constantly measures the test motor’s torque at its output shaft, logging it for later analysis.

Prolonged and arduous tests are often run, simulating on and off road, every type of surface, steep gradients, gentle gradients, all sorts of extreme weather, heavy loads, shock loads and every other anomalous behaviour you can imagine.

Before the rolling road was built, the analysis regime was based on test driving around the town, but consistency and repeatability were, of course, impossible to achieve. The rolling road has been used constantly since it was built, so its reliability and ease of use are major issues, both of which are helped by the TorqSense.

As development engineers, we at Sensor Technology never know what our next job will be. But it is heartening to think that we are making such a direct contribution to healthcare and medicine.

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@sensortech #Medical #Manufacturing

Weighing the load!

The handling of dry bulk materials used to be a completely manual process, but it is now being increasingly automated in a drive to reduce both the costs and the risks of injury, while also increasing throughput and accuracy. Tony Ingham of Sensor Technology reports on some of the new technologies behind these developments.

The demands of today’s highly competitive commerce and modern industry are such that speed, accuracy and efficiency are required within every process. This includes the handling of dry bulk materials, such as grain, coal, aggregates, minerals and chemicals through every stage of their logistical journey from producer through processor and distributor to eventual end-user.

Not surprisingly, major handling facilities are now highly computerised, and often have a control room with a bank of computers, which would not look out of place on the USS Enterprise. Their job can be summed up as collecting information from many, many different sources, collating it, and then calculating the optimum procedures for every stage of the overall process.

The computers represent a well-developed technology and their data processing abilities, while hugely impressive, are based on relatively simple logic algorithms. The technology developments that are driving the advancement of bulk handling are at the sensing end of the system, where the prevailing conditions of the moment are detected and converted into data signals for the computer to use.

"Sensors are the eyes and ears of the computerised system,” says Mark Ingham of Sensor Technology Ltd, one of the companies at the forefront of developments. “They constantly monitor what is going on and feed real-time data to the computer." One of their latest products is a load sensor with a difference. Called LoadSense, it is wireless, so is ultra easy to deploy in situations like docks and grain banks where installing cables would be difficult – and maintaining them even harder!

LoadSense is online permanently and constantly sends real-time load value signals to either the central computer or its own local computer or receiver for preliminary analysis. It can be used in all types of materials handling operations, but is particularly useful for measuring loads in augers and on conveyors, where materials are ‘in flight’, so the load varies constantly with time.

LoadSense can be thought of as a two-part system. First, is a strain gauge-based stainless steel tension type sensor, with a twin antenna transmitter built into it for transferring the load data the instance it is generated. The second part of LoadSense is the receiver, which can be either fixed in place or handheld. The receiver reads, displays and records the data and can pass it onto the central control system for integration with other data streams for analysis.

The receiver includes an in-built 32MBit memory, which can hold up to 280 hours of data, thus providing both a local control station and a backup databank for the wider system. It is also notable that each receiver can collect data from several nearby load sensors simultaneously, in a range of up to 100m.

Importantly, the LoadSense transmits using the worldwide licence-free frequency of 2.4GHz, so can be installed and operated freely without disrupting other radio-based equipment. In operation, data is transmitted at up to 10 times a second, so LoadSense is constantly updating and providing real-time information so that operations can be optimised for best results.

The key benefits LoadSense brings to materials handling installations include: the simplicity of wireless installation, easy reconfiguration, its long battery life (which is complemented by easy recharging), and the dual antennas which represent just one part of the overall rugged design.

Technology transfer.
In fact, Sensor Technology originally developed LoadSense for use with helicopters, as Mark explains: “Helicopters often carry cargo in nets slung from cargo hooks on their underside, and it is important that the pilot knows its weight. A conventional load sensor in the hook could provide this data, but wiring it back to a readout in the cockpit would invalidate the craft’s Certificate of Airworthiness, implying the need for expensive recertification. When we heard about this dilemma, we instantly realised that a wireless solution was the answer!”

Since its development LoadSense has been adopted by many other industries, too. For instance, in forestry tree harvesting is often best done by pulling the trees over with a large tractor – this uproots them, so that the whole tree is recovered and also the ground is left stump-free so is in better condition for reuse – a LoadSense on the pulling cable will provide the tractor driver with vital live information and also collect data on harvest volumes for commercial analysis. They have also proved popular in the fly towers of theatres, allowing scenery and backdrops to be raised and lowered quickly and safely, for materials monitoring in road laying and civil engineering, in food production and processing, etc.

Sensor Technology has also transferred another of its technologies, TorqSense into the world of dry bulk materials handling. Like LoadSense, TorqSense uses a radio frequency signal transfer technique , but its sensing head measures the rotary torque in a turning shaft.

"Consider a screw conveyor or auger, both of which are driven by a rotating motor shaft," says Mark. "If this is rotating empty, it requires little power from its drive shaft. If it is half full, it requires rather more, and if it is completely full its needs a lot more.

"The same goes for speed – the faster, the more power consumed. Also, the denser the material being conveyed, the more power required. By constantly measuring the torque in the driveshaft, we can determine the volume and weight of material being conveyed."

Both LoadSense and TorqSense have been successfully used in dry bulk materials handling installations and have proved their worth many times over. As handling inevitably becomes more automated, the need for such technologies will become more and more crucial.

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@sensortech #MaterialHandling #Load

Breakthrough in powertrain innovation.

University College London's (UCL) HyperMile Racing Team proudly announces a pioneering advancement in automotive technology aimed at revolutionising efficiency in the Shell Eco-Marathon. Harnessing the power of Sensor Technology's TorqSense rotary torque transducer, the team has developed an innovative powertrain system poised to redefine performance standards in the eco-racing sphere.

UCL's HyperMile Racing Team, known for its dedication to pushing the boundaries of sustainable transportation, has partnered with Sensor Technology to integrate cutting-edge torque measurement capabilities into their vehicle design. This collaboration has resulted in the creation of a highly efficient powertrain system meticulously engineered to maximise energy utilisation and minimise waste.

The use of Sensor Technology's TorqSense transducer provides the team with real-time insights into the performance dynamics of their vehicle, enabling precise adjustments to optimise efficiency on the track. By leveraging this advanced sensor technology, UCL's HyperMile Racing Team aims to achieve unprecedented levels of fuel efficiency and endurance in the upcoming Shell Eco-Marathon.

"We are thrilled to unveil our latest innovation in collaboration with Sensor Technology," says Bartol Vahcic, Technical Director of UCL's HyperMile Racing Team. "By integrating the TorqSense transducer into testing our powertrain system, we are confident that we can push the boundaries of eco-racing and set new benchmarks for sustainability and performance." 

The Shell Eco-Marathon serves as the ultimate proving ground for innovations in energy efficiency, attracting top engineering talent from around the world. With the introduction of their groundbreaking powertrain system, UCL's HyperMile Racing Team aims to make a significant impact on the future of sustainable transportation and inspire the next generation of eco-minded engineers.

This years competition takes place on May 22nd -24th at Circuit Paul Armagnac, Nogaro, (F), and Sensor Technology will be willing the UCL team on.

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Deep probing into machinery.

Sensor Technology has extended its new range of torque sensors with a model that has the sensing head and electronics in separate housings. This has two advantages: the sensing head can fit into very confined spaces, and the electronics can be located in a position where they are protected from physical damage, dust, dirt, moisture, electromagnetic forces, etc.

The new TorqSense SGR530/540 series operates on the same principle as all the other SGR510/520 units, namely a full four element strain gauge bridge. This uses four individual stain gauges affixed to the drive shaft; each measures the deflection of the shaft in a different direction as it rotates under load. The electronics collects readings from all four gauges and calculates the torque value.

Sensor Technology launched the TorqSense SGR510/520 range in 2020 as the successor to its RWT range which worked on surface acoustic wave (SAW) measurement and detection. It has specialised in real-time torque measurement for over forty years, and pioneered the development of wireless technologies that use radio frequency pickups rather than hard-wired solutions involving delicate and unreliable slip rings.

Initially launched in sizes up to 500Nm, interest in the SGR sensors was so high that the introduction of larger sizes up to 13,000Nm was brought forward 6-12 months to December 2020.

"Because of our experience with the RWT, we have been able to compress the development times for the new SGR models considerably,” says Sensor Technology’s Mark Ingham. “So, we have been able to react to specific enquiries from individual users and bring forward model launches. "

The new range is designed to meet emerging user requirements, notably accurately recording transient torque spikes. In the past transducers didn’t have the bandwidth to capture these spikes, so they were ignored. However, advances in automation, continuous operation and the increasing need for accurate track and trace data has led to the need for more detailed measurement and analysis, as Mark explains:

"A single spike could indicate say the wrong amount of an ingredient being added to a compound or an over-sized workpiece, both of which could affect product quality. A series of spikes would probably suggest the beginnings of a problem within the machinery, so their detection gives the plant engineers an early warning”.

In use, a rotor mounted ultra-miniature microcontroller, powered by an inductive coil, measures the differential values in each strain gauge and transmits them back to the stator digitally, via the same coil. The SGR510/520 series transducers then use state of the art strain gauge signal conditioning techniques to provide a high bandwidth, low cost torque measuring solution with high overrange and overload capabilities.

An advantage of the design of the SGR torque sensors is that they automatically compensate for any extraneous forces, such as bending moments, inadvertently applied to the sensor. They also offer high sensitivity and have a wide temperature tolerance, attributes that are required more and more and production machinery becomes more and more sophisticated and performance demands increase.

Other advantages of the SGR range include: elimination of noise pickup and signal corruption associated with slip rings and hard wired solutions, a 400% mechanical overload limit with accurate torque measurement even at these extremes, and multipoint calibration to eliminate linearity errors within the sensor.

All units are accurate to +/-0.1% and resolution to +/-0.01% of the transducer’s full scale. Other features include an adjustable moving average filter, power supply range from 12VDC to 32VDC, user settable analogue output voltages, and RS232, USB, CANbus and Ethernet comms options.

"Like the RWT sensors the new SGRs can integrate digitally with TorqView software and LabView virtual instruments," concluded Mark.

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@sensortech #Manufacturing #Torque

Putting the cap on correctly.

A vital role in packing leading edge medical test kits for management of critical illnesses.

Axis-Shield is a world leader in inventing new markers for identifying cardiovascular and neurodegenerative diseases, rheumatoid arthritis, sepsis, vitamin deficiencies and diabetes. Spotting early signs of such conditions during routine medical check-ups means treatment can be started in a timely manner, which leads to improved patient management, either curing or managing the problem.

The compounds it develops are initially produced in low volumes, where automated processes are not appropriate. This moves to medium volume production once the product has been proven, approved and certified and the medical fraternity begin using it. Some compounds later move into high volume production, but it is in the very nature of medical advancement that in other cases Axis-Shield will keep on improving the formulations and developing new products fairly quickly. Thus Axis-Shield has a need for highly efficient medium volume packaging solutions that guarantee accurate and consistent adherence to performance parameters.

This led the company to commission a bespoke packaging line that could handle multiple products in a variety of different packaging formats at a rate of around 500-2500 units per hour. The line fills bottles or other forms of container with the compounds, caps them, labels them, groups them into multi-packs, applies outer wrappers and overprints key data such as production date, use-by date, storage, handling and usage instructions, etc. “Capping the bottles is a critical part of the process,” explains Dean Harper of the company. “Our line can work with two sizes of cap and each one must be tightened to just the right level of torque to within pretty tight tolerances.”

A cap that is too loose may lead to spillage of the marker, which is usually very expensive, during transit or handling. A cap that is fitted too tightly may cause upset to the patient or medical staff, who are both likely to feel stressed if smooth medical procedures are upset. Equally, forcing open an overly tight cap could result in spillage. “Our packaging line has four capping stations and each one is fitted with a TorqSense transducer,” explains Dean. “These work in conjunction with a computer to ensure the correct level of tightness and record the data for traceability records.” TorqSense is unlike any other sensor in that it does not rely on delicate slip rings to transmit torque readings. It does this wirelessly using radio signals transmitted from a pick-up located near to, but not actually contacting the rotating drive shaft of the capping mechanism.

“The capping process is essentially simple,” says Dean, “but you have to allow for a fast cycle time and the need to guarantee torque while ensuring total sterility.” TorqSense met the design criteria of robustness, simple high speed operation and non-contact for sterility.

Mark Ingham of Sensor Technology gives the details: “TorqSense was ideal for this application; we just needed to work out mounting arrangements. We supplied the sensor with our standard TorqView software which both displays readings in real time and archives them should analysis or track and trace be an application requirement. Being wireless, TorqSense does not need to physically contact the bottle caps or shaft of the torque head it is monitoring.

Digital Inductive telemetry is used to transfer strain gauge sensor data from the rotating shaft. This method enhances reliability and precision of the torque measurement by digitizing the strain gauge signals very close to the sensors on the shaft which eliminates much of the noise associated with millivolt signals, slip rings and long cable runs. This also improves the temperature coefficient by removing the thermocouple effects of the cable. The digital data is also integrity checked using a checksum so only valid data will be presented to the end user.

For Axis-Shield, the software was required to do two things: run the torque up to a set level within tolerances, and record the actual value achieved. This secures the cap to the bottle at a level of tightness that will ensure security and sterility, yet is at a level that can be opened relatively easily by an adult. The logged values are saved to a hard drive to provide a permanent record for traceability purposes. 

Dean explains: “Diagnostic fluids are distributed widely, often globally, so they may be stored for months before use. Tracing each bottle’s origin would be practically impossible without full records being automatically produced and saved to a central location. TorqSense provided a solution to this complex but critical problem using an out of the box technology.”

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• See also Top Ten Torque Tips (8/2/2024)

@sensortech #Automotive #Torque

Ten top torque tips.

Driveshafts deliver power as a rotary force, and in most applications there is a need to know the amount of power in the system. Getting measurements from a turning shaft requires some engineering ingenuity, and Tony Ingham from Sensor Technology runs through the basics.

Tony Ingham

01. Torque is a turning force and, because every material from which a driveshaft can be made has a degree of elasticity, it is also a twisting force that deforms the shaft in the direction of rotation. This deformation is usually only very slight, but it is massively important when it comes to measuring torque.

02. Probably the most common way to measure torque in a turning shaft is to glue strain gauges onto it. A strain gauge is effectively a zig-zag of wire encapsulated in a flexible substrate for protection. When the shaft twists under torque the zig-zag will be stretched, which will change its electrical impedance. Therefore, the resistance of the wire is proportional to the torque in the shaft. However, there is a problem in that electrical leads connected to the strain gauges would wrap around the shaft as it turned and eventually snap. Fortunately, there are solutions to this, which we will look at later.

03. In fact, it is normal practise to use not one, but four strain gauges spaced along the shaft. All are at 45deg to the direction of rotation, two to the left and two to the right. These are then connected into a Wheatstone bridge configuration, which produces an electrical output that is linearly proportional to the torque in the shaft as it rotates. The circuitry is completed with a power supply, amplifier and a display, recorder or computer. These are usually mounted somewhere close to the driveshaft in a secure, static location.

04. We now come onto the elephant in the room. How do we connect the stationary parts of the circuit to the spinning Wheatstone bridge? One answer is slip rings – collars mounted onto and standing proud of the shaft, which contacts static brushes.
Unfortunately, the slip rings are rather delicate; so much care must be exercised in their use. Also, they need to be set up with some precision so that a constant and even contact is maintained in operation.
Because of brush wear, slip rings need regular attention and they are not really suitable for long-term use, nor for deployment in harsh working environments. It is also notable that the contact between the stationary brushes and rotating collars will create a degree of electrical noise which, particularly at higher speeds, will interfere with signal transmission. A final shortcoming of slip rings is that they create a drag force, which must be accounted for in signal measurements and frequently checked to make sure that it has not changed in value.

05. An alternative to the slip ring is the rotary transformer, sometimes called an inductive loop. This consists of two adjacent electrical coils – one static the other rotating with the driveshaft – the relative motion of which induces a current in the transducer.
There is no physical contact between the coils, nor between shaft and transducer, yet power and signals are passed between them. This overcomes many of the drawbacks of slip ring systems; set up is easier, operation is more robust, there is no friction and higher speed operations can be accommodated.
However, every rotary transformer will have a maximum operating speed due to its inertia. They are also susceptible to noise and errors, especially if the coils become misaligned.

06. The next development on a torque sensor is the type that is based on radio telemetry. These operate on the internationally licence-free 2.4GHz frequency band and are based on the concept of mounting a receiver pickup so that it can communicate with the strain gauges. The pickup can actually be many metres from the driveshaft, so long as communication is maintained.
Installation and maintenance are straightforward because there is no slip ring to adjust, coils to align or cabling to accommodate. However, a battery is required to power the signals, which although small and long lasting, does require consideration.

07. Perhaps the ultimate type of torque sensor is that based on the detection of Rayleigh waves or surface acoustic waves (SAWs). These are non-contact and use piezoelectric strain gauges. In a SAW sensor, the surface waves are produced by passing an alternating voltage across the terminals of two interleaved comb-shaped arrays, laid onto one end of a piezoelectric substrate. A receiving array at the other end of the transducer converts the wave into an electric signal.
The wave frequency is dependent upon the spacing of the teeth in the array and the direction of wave propagation is at right angles to the teeth. Therefore, any change in its length, caused by the dynamic forces of the shaft's rotation, alters the spacing of the teeth and hence the operating frequency. To measure the torque in a rotating shaft, two SAW sensors are bonded to a shaft at 45° to the axis of rotation. When the shaft is subjected to torque, a signal is produced, which is transmitted to the adjacent stationary pick-up via the RF couple.
Interestingly, SAWs were first detected by 19th century gentleman–scientist and Nobel Laureate Lord Rayleigh when he was investigating the cause and effects of earthquakes.

08. Selection of the type of torque transducer will be based on many considerations including: the working environment, the expected length of operation, the rotational speed of the driveshaft, mechanical connection options and costs. There is no overall ‘best’, but an optimum choice for each individual situation.

09. Positioning a torque sensor can be a complicated decision if a true reading is to be obtained. Inaccuracies can creep in due to the effects of adjoining elements in the drive train, the damping effect of the driveshaft’s own end couplings and drag caused by contact-type sensors.

10. The final piece of advice is that expert help is usually available through the company supplying your torque sensor. Availing yourself of this service will probably save time, money and frustration.

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@sensortech #Automotive #Torque

High perforamnce Formula EV for students.

High performance electric cars are being developed across Europe for Formula Student, an engineering education competition like no other. The team from Instituto Superior Técnico, Lisbon, Portugal may have a secret weapon in the form of a test bench based upon a wireless torque sensor.

Formula Student (FS) aims to develop enterprising and innovative young engineers and encourage more young people to take up a career in engineering. It is designed to test students’ abilities and demonstrate their capabilities to deliver a complex and integrated product in the demanding environment of motorsport.

Entry into the competition usually forms part of a degree-level project and is viewed by the motorsport industry as the standard for engineering graduates to meet, transitioning them from university to the workplace. Many FS participants go on to have amazing careers either in motorsport or elsewhere.

Sensor Technology Ltd has supplied a TorqSense system to the Formula Student team at Lisbon’s renowned technical university, the Instituto Superior Técnico, so that they can develop a high performance electric motor for their car. Their efforts will be doubly impressive as the power/weight ratio will far exceed any previous electric motor development undertaken in Portugal.

FST Lisboa is one of Portugal’s most successful Formula Student teams, having been actively involved since 2001. With seven prototypes from past events, the team has achieved national recognition for its innovative engineering and project management. In fact the team’s fourth car was the first ever high performance electric car developed in Portugal, while its 2017 design was the first four-wheel drive electric prototype completely developed in Portugal.

This year the team, composed of students from several engineering courses (Mechanical, Naval, Electrical, Aerospace, Informatics and Industrial Management), is pushing to even greater heights and developing its own electric motors.

Henrique Motta, who is studying industrial engineering and management and is also Sponsor Manager for FST Lisboa, explains that this year’s entry is based on the team’s previous electric car which was the first to have all-wheel drive transmission. Thus much of the focus is now on developing, testing and refining the electric motor.

He gives some details: “TorqSense has an important role with us. We have been developing our own electric motors for the past two years and now we are starting to build production units that will be fitted into the car, which is designated FST 08e. As a very important part of the motors’ development, we need to test them rigorously and log huge amounts of performance data so that we can analyse it and work toward an optimised final design.” The TorqSense sensor will allow the team to measure the motors’ torque to predict its behaviour once installed in the car. They will be testing motors to their limits in the test bench, so should eventually be able to predict completely how it will perform in all circumstances.

The testing regime has been developed so that the TorqSense will be used in all bench tests to fully model all the performance characteristics of the prototype motor. The tests will go a maximum speed of 20 000rpm and maximum torque of 30Nm.

TorqSense has often been used in dedicated test benches, for prototypes as varied as wind turbines, industrial fans, windscreen wiper motors, unmanned drones and model aircraft as well as for many electric vehicle projects. It is often the preferred solution because, being wireless, it is easy to set up for each new test run and does not require a large amount of wiring and slip ring setting each time.

However FST Lisboa says it was primarily attracted to TorqSense because of its connectivity, as Motta explains: “TorqSense allows us to easily connect other hardware and software solutions using USB or CAN bus. We also like the ease of use of Sensor Technology’s software products such as TorqView and the ETD Transducer display, which make the visualisation and logging of data a simple one-step process.”

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@sensortech @istecnico #Automotive #Torque #Portugal

Monitoring of mobile harbour equipment.

Tony Ingham of Sensor Technology Ltd explains how monitoring the work rate of cranes, loaders and unloaders means their performance can be optimised and downtime for maintenance can be scheduled for minimum disruption to operational requirements.

The increasing globalisation of the world economy is pressurising ports, docks and harbours into handling ever-increasing volumes of cargo, so mobile harbour equipment has to work efficiently and reliably at all times. 

Importing and exporting of dry bulk cargos, from minerals to grains, fertilisers to cement, wood chips to agricultural products, is almost exclusively a maritime operation. Thus there is a need to load and unload ships and barges, and in the modern world this has to be done quickly, efficiently and safely.

So as the volume requirements of world trade increase, harbour operators must ensure their loading/unloading equipment is in top condition, always available for use, and able to adapt to new operational, commercial and safety requirements. The best way to maintain such equipment is constant monitoring while it is working. This will allow the work to be totalised so that pre-emptive maintenance scheduling can be optimised, and will also instantly pick up early signs of emerging problems, such as sticking bearings.

The work done is directly related to the totalised load lifted, a parameter that crane and loader operators should also be measuring for both safety and commercial reasons. Constant load monitoring used to be very difficult, but Sensor Technology has developed the perfect solution. Called LoadSense, it was originally used with helicopters carrying underslung loads in cargo nets and has now been adapted for use on ground-based materials handling equipment.

The technology involves a sensor being fitted to each crane or unloader. Once installed this does not interfere with handling operations at all, but constantly sends real time data via a wireless link to a computer, where it can be displayed, stored, totalised and analysed to provide performance information to the operators and billing information for the customers.

LoadSense is an intelligent load sensor that can easily be integrated with a mobile harbour crane. Designed and manufactured by Sensor Technology in Banbury UK, it is fully automatic so causes no disruption to normal operations. Special training is not required; instead comprehensive and easily understood information becomes instantly available to operators and managers alike.

The LoadSense sensor is based on proven strain gauge technology, and is calibrated as standard in the range 1-50 tonnes, with other ranges available on request. It constantly monitors the load and transmits this wirelessly, using the unrestricted 2.4 GHz waveband, to a receiver for onwards transfer to the control computer. This enables accurate load data to be displayed, typically via a colour touchscreen computer, running Windows XP. The screen shows real time measurement of the load, while the computer records and analyses it.

LoadSense has become a favourite amongst harbour crane operators as an important enabling technology to improve safety, asset availability, productivity and profitability. For instance, you may need to know how much material you have transported, or you could be handling two or more materials simultaneously which need to be accounted for individually. A common scenario is where multiple customers’ cargos are being handled at the same time; here LoadSense gives operators the information they need in order to invoice each appropriately.

LoadSense also enhances safety and prevents dockside handling equipment from failing catastrophically. There are typically two reasons for such failures:

• Overloading the crane with too much weight. Because LoadSense is constantly producing a digital signal, it is easy to set up the control computer with an overload value that will trigger an alarm if it is breached. It is equally simple, and practically better, to set the computer so that it will cut out lifting operations if the overload limit is breached, thus ensuring excessive loads are not raised off the ground.
• Aging cranes and unloaders can suffer fatigue failure. LoadSense can be used to keep count of the number of operational cycles performed, and signal when the equipment’s design life is being approached. An inspection can then be conducted to determine the likelihood of imminent failure and remedial works that can be undertaken.

In conclusion we can say that to be profitable harbour operators need to work their dockside handling equipment long and hard and that the best way to ensure reliability and safety is by constantly monitoring the load and interpretation of the ensuing data. LoadSense from Sensor Technology makes this requirement completely automatic and foolproof.

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@sensortech #Pauto

Ensuring safe fire protection.

Ultra-reliable is the only standard acceptable when it comes to building, testing and maintaining water pumps for fire fighting. To ensure all of its pumps are fully able to provide maximum performance instantly, under all circumstances, Ruhrpumpen has built a dedicated fire pump centre in Lancing, West Sussex (GB) and fitted its test-rig with "the best torque sensors it could find on the market".

David Gentle, Ruhrpumpen Industrial Europa Product Line Manager for EU Fire Systems, says: “We are a very high tech industry, but there is also a lot of human intelligence and input into our operations. We really value the support from the team at Sensor Technology and know we will always get a quick response from them, no matter when we call. TorqSense transducers are lightweight, easy to use and we have recommended their adoption by our group subsidiaries around the world, all of whom are FM/UL certified."

Ruhrpumpen is a global leader in high technology pump systems and is a major player in industries such as oil and gas, water distribution, chemical production, continuous processes, and nuclear power. Identifying fire fighting as a crucial sector, it set up Ruhrpumpen Industrial Europa Ltd (RPIE) a Factory Mutual (FM) and Underwriters Laboratories (UL) certified manufacturing facility for fire water pumps in Britain. The FM and UL Approvals Bodies audit the facility quarterly, inspect calibration certification and carry out flow, pressure, power, NPSH (net positive suction head) and other relevant tests as required, ensuring that the facility maintains world-class standards at all times.

Ruhrpumpen Industrial Europa Ltd’s state-of-the-art fire pump manufacturing centre is fully equipped to design, assemble, test and package fire pumps for European market requirements. It can also produce standard and highly-engineered pumping systems for a wide range of other applications industries, often using the technical requirements of firefighting to set benchmarks in other industries.

In addition to pumps and systems for use in Britain and Europe, the facility also provides parts and support for highly-engineered pump equipment to other Ruhrpumpen companies around the world, and offers product and system testing, training and specialist consultancy services.

With the test-rig TorqSense transducers measure and record instantaneous torque levels in rotating pump drive shafts, with analysis of the data confirming real-time performance standards, in testing operations.

TorqSense comes in a range of sizes for measuring torque, both rotary and static, from 10mNm up to 13,000Nm. Different ranges are based on different technologies, including full four element strain gauge bridges and optical measurement. None of these require hard wiring with slip rings, instead being designed for use with wireless radio frequency pick-ups which make set up and adjustment fast and simple.

Working with clients, experts from Sensor Technology can recommend the best transducer for each application.

As is a requirement in all fire pump testing, the torque transducers are all regularly calibrated by an independent ISO 17025 accredited calibration laboratory.

There is also a full range of data display, recording and analysis interfaces. Again, it is the work of moments to integrate these with the sensor heads. However, with fire water pumps being such a specialised and highly regulated field, Ruhrpumpen decided to use bespoke data systems developed to directly address the needs of the industry. With these, data is recorded and analysed in Ruhrpumpen’s own performance test app before the final pump Test Report is made available. Naturally everything is tested and verified by qualified independent bodies on a regular basis.

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@sensortech @ruhrpumpen #Pauto

To guarantee valve actuator performance.

Rotork Controls has established a global reputation for robust and reliable valve actuators, operating in some of the world’s most demanding and critical applications. Thorough testing of the motors used in the actuators is one of the keys to this assured performance, with TorqSense transducers from Sensor Technology playing a vital role in the test process.

Rotork is the world’s leading manufacturer of electric, pneumatic and hydraulic valve actuators and associated control systems, valve gearboxes and valve accessories. The company’s electric valve actuator division offers an electrical solution to industrial valve control and actuation applications of virtually any size, description and complexity.

Its capabilities encompass actuators and control systems for new plants, plant extensions and upgrades, together with life-of-plant support. The division’s unrivalled range of products offers a robust and economic solution for every valve duty and operating environment.

Rotork Controls chief development engineer Geoff Beeho comments: “If you look at something like an oil line, then any failure of the valve actuator could potentially be costing millions of dollars a day. We have to be able to guarantee the performance of the actuators in the most demanding conditions, so testing is vital. TorqSense torque transducers from Sensor Technology are a key element of our test rigs.”

Companies and businesses around the world rely on Rotork actuators, in applications as diverse as power generation, water and sewage, industrial processes, subsea, marine, HVAC, incinerators and cement plants. Common features in many of these applications are challenging environmental conditions, extremes of temperatures, and high costs associated with any downtime. Because of this, absolute reliability of the valve actuators is vital.

The company designs custom actuator designs built around motorised gearboxes, using non-standard open frame motors. “We use a variety of motors depending on the particular application, including DC motors, single-phase motors and three-phase motors, but we don’t rely on off-the-shelf products. Instead, we use open frame motors that we integrate directly into our own systems.

“Performance testing is very important,” he continues. “The duty cycle is atypical – our motors are not in continuous use, only running intermittently and for short period. What is important to us is the short term ratings, and this data isn’t always readily available. We have to have performance data that will tell us exactly what we need to know about the motors in these most demanding applications.”

They designed their own rig to test the motors, with Sensor Technology TorqSense transducers at its heart. “We needed non-contact torque sensors in the rig. The early design used magnetically coupled torque sensors but we were never completely happy with these. So when we upgraded the rig to be able to perform a wider range of tests, we took the opportunity to look around the market and we found the TorqSense transducers.” 

“The TorqSense transducers immediately struck us as being a much more robust solution, better suited to handling the torques we were subjecting them to,” comments Beeho. The common practices of over-specifying a motor that guarantee reliable operation in standard applications simply don’t apply in valve actuation. “Motor sizing is critical,” he continues. “If we put in a motor that is too big, then we can risk damaging the valve. We can use motors that appear to be under-rated, but because our duty-cycle is so short we can get better performance from the motor. But the performance data to support this sort of motor use isn’t always available, or isn’t always reliable, so we need to perform our own tests. We also need to know how our motors will handle extremes of temperature in given applications so that reliability is never compromised. The TorqSense transducers allow us to make all the required tests.”

An advantage of the TorqSense transducers in the Rotork test rig is that they provide both analogue and digital outputs. “This has proved to be a real bonus,” says Beeho. “Not only can we use one output to check the calibration of the other, but it also means we have the flexibility to use both outputs performing different tests. For example, we might use the analogue output to feed torque and speed data into the power analyser during a performance test, and then use the digital output for a temperature test. Here, we run the motor for 15 minutes at constant torque and see how hot it gets. The output from the TorqSense transducer allows us to close the loop so that we can keep the torque constant.”

In any application, the fundamental considerations are the actuator’s ability to overcome the resistive forces of the valve, and the dynamic performance requirements to enable the valve to adequately meet the process demands. With its comprehensive testing procedures built around the TorqSense transducers, Rotork Controls has the confidence that its electrically operated valve actuators will always meet the application requirements.

@sensortech @rotork #PAuto  #TandM

Torque sensors for airline safety.

The aerospace sector is renowned for its safety standards and a whole industry has grown up to provide equipment and services for testing aircraft and their subsystems.

Airliners are subject to tremendous loads as they land and take off, from the touchdown of the undercarriage, to the back-thrust of the jet engines as they slow the aircraft on the runway and the wind pressure on the flaps and flight control surfaces when they are lowered to provide air-braking. Furthermore, these loads can increase exponentially in difficult or emergency situations, so it is essential that the relevant parts are regularly tested and recertified as fit for purpose.

SGN Electrical has recently built two test rigs, one for testing the landing gear, the other for the flaps on the tail plane, that are helping ensure transoceanic-scale airliners capable of carrying hundreds of passengers can land safely and reliably every flight.

SGN is well-known for its electrical contracting services to most industries in the south east, including at the region’s main airports where ‘right first time and right on time’ is the expected standard no matter how challenging the work. Its engineers have a wealth of experience in inspection and testing, from small installations to hazardous areas, aerospace and other specialist fields. As well as electrical skills it is equally well versed in mechanical engineering, so was a natural choice to build the test rigs. One rig tests the ballscrews used to raise and lower the tail plane flaps. Rather than just a function test, the rig simulates the high speed air flow over the aircraft while it is in flight, using a hydraulic actuator to apply a measured but varying load to the ballscrew.

The second rig is for testing the landing gear by simulating the loads on the main lead screw as the wheels are lowered and touch down. This includes the extra loads that are likely to be experienced in bad weather and the sudden shock loads that might occur in an emergency landing.

Both test rigs use a TorqSense transducer from Sensor Technology as their main element. TorqSense is much-favoured by test rig builders as it is a non-contact technology that uses reflected radio waves to measure the torque in a rotating shaft.

“There is no need to spend time setting up fiddly slip rings every time you use the rig,” explains SGN’s Scott Nicholson. “You just point the sensing head at the test piece and real time data is collected. We run this through a standard Sensor Technology controller and the results are both displayed on a digital screen and stored for later analysis.

“Using TorqSense makes it easy to build a test rig, but far more importantly it makes the tests much, much quicker and easier. Therefore more tests can be done in a given time, which means results can be checked, double-checked and checked again – which is pretty much the operating procedure required for aircraft safety.”

@sensortech #SGN #Aerospace #Automation

But who'll do the washing up?

Real time process control for food manufacture has come a significant step closer, thanks to pioneering research work at University College Dublin (IRL) into viscosity measurement techniques for characterising the flow and mixability of highly non-Newtonian fluids. At the heart of the researchers' experiments is the TorqSense transducer made by Sensor Technology, which monitors the constantly changing flow characteristics of materials as diverse as tomato ketchup, chocolate, pasta sauce and chicken tikka massala as they are mixed.

Ireland's national economy has always had a strong agricultural element and more recently considerable value has been added to this by becoming one of Europe's foremost manufacturers of processed ingredients and ready meals.

Many foods are presented in a sauce or as what physicist could describe as a neo-liquid and can be produced in a process-type environment. But to date real time control has been virtually impossible due to the non-uniform nature of the food, which may contain particulates, fibres, vegetables, meat, nuts, raisins, biscuits etc.

"Real time process control is vital if food processors are to achieve the ultimate in product quality," says PJ Cullen, who leads the research team. "To achieve this the sensor has to be pretty special to detects the changes with sufficient sensitivity, yet be robust enough for regular wash-downs and general industrial abuse. Of course it must not compromise hygiene standards and regimes either. We tried a number of sensors and TorqSense stood out as by far the best at meeting all our needs."

PJ and his colleagues have simulated food processing techniques in a number of different laboratory rigs, one of the most used being a helical ribbon mixer similar to those employed by manufacturers for mixing ingredients together. Often the key requirement is to mix sufficiently to achieve a uniform dish, but not to waste time and energy by over-mixing.

"We do this by monitoring the torque on the mixer's shaft, as it will move to a steady state (within the characteristics of the given recipe) once fluid uniformity is achieved," says PJ.

Summing up he continued, "It has given us exactly what we needed at low cost, and it is simple to use and reliable - key requirements in a busy lab - but also very attractive to full scale process control environments. The only drawback of our research programme, is all the washing up after working so closely with so many different dishes all day!"

@sensortech @ucddublin #Pauto #Food #Resaearch #Ireland

Low capacity torque sensor.

The low capacity models of Sensor Technology’s non-contact torque sensors offer accurate measurement down to 200mNm (0.2Nm), for applications such as precision and high speed robots, medical devices, protheses and implants, small drives and micro motors.

The new TorqSense SGR 510/520 torque sensors cover capacities from 0.2Nm to 1Nm, making the full range 0.2Nm to 13,000Nm. The bigger units in the SGR family are designed for use in machine tools, production and processing plant, heavy duty pumps and similar large scale installations.

Based on a full four-element strain gauge bridge design, the SGR sensors have the ability to accurately measure and record sudden spikes in torque load. This ability is becoming increasingly important in automated machinery, integrated systems, test rigs and continuously monitored plant.

“Torque spikes can have an immediate effect on operations, or may indicate the beginnings of a problem,” explains Mark Ingham, Sensor Technology’s Sales Director. “The SGRs are designed to accurately record all torque data from any type of system, big or small, simple or complex, yet be robust enough for use in virtually any environment.”

The TorqSense SGR measures the torque 4000 time per second and uses high performance signal conditioning to provide a corruption-free, high bandwidth torque monitoring solution. This is further enhanced by 250% overrange and 400% overload capabilities, elimination of side and end load errors and real time temperature compensation. The non-contact signal transmission means the sensor exerts no load on the shaft it is monitoring, while maintenance-heavy slip rings have been designed out.

Three analog output channels on the 511 mean the SGR can measure real-time speed and power alongside the torque monitoring. A third output is dedicated to self-diagnostics and/or status functions. An Ethernet gateway module can also be fitted to the unit.

As well as analog outputs, TorqSense SGR 520/521 is also fitted with digital outputs for interfacing with state of the art instrumentation and laptops. Options include RS232, CANbus and USB. A digital input is provided so that the 520/521 can be set up directly from a PC running specialist configuration software such as Sensor Technology’s TorqView or LabView.

“Using the USB output, it is possible to connect upto 10 SGR 520/521s into one fully integrated system,” comments Mark, “allowing even the most complex installations to be comprehensively monitored from a single workstation. Torque measurement is playing an increasingly important role in modern plant and machinery monitoring and control, enabling steady increases in efficiency, productivity, availability and accuracy - all key drivers in the advance towards tomorrow’s technology.”

@sensortech #Pauto

Tested but not touched.

TorqSense, a non-contact digital torque monitoring system that could guarantee an infinite lightness of touch has proven to be the only way to test the seals of super high performance vacuum systems.

The ultimate fields of precision manufacture, such as electronics, biophysics and thin film deposition where tolerances are measured in atoms, are often conducted in hard vacuum to remove airborne contaminants and avoid the performance reducing effects of tiny air movements.

However the vast majority of vacuum chamber designs require seals for rotary drive shafts (called rotary feedthroughs) and ‘feedthroughs’ for the passage of materials, components, tools and finished products. In high vacuum applications conventional seals are unlikely to be able to achieve the performance specifications required, so magnetic fluid seals are used.

A ferrofluid is a stable colloidal suspension of sub-domain magnetic nano particles in a liquid carrier. The particles, which have an average size of about 100Å (10 nm), are coated with a stabilising dispersing agent (surfactant), which prevents particle agglomeration even when a strong magnetic field gradient is applied to the ferrofluid. With over thirty years of experience producing seals for the world's most demanding applications, Ferrotec of Woolwich in London is able to optimise ferrofluid materials for the most extreme performance requirements and incorporate them into bespoke vacuum system designs.

“About half of our work is to bespoke design,” says Jeff Lewcock of Ferrotec, “and we have to test every seal to the nth degree to meet out customers specifications. To test the feedthrough it is mounted onto a vacuum chamber that is connected to a helium leak detector. Helium is then spayed onto the feedthrough and the leak rate observed during static and dynamic running.”

As part of the test the starting and running torque of the seal are measured and the power loss through the seal is calculated. These readings allow Ferrotec to troubleshoot the individual seal, analyse the design’s performance and add to their knowledge base. “With the sort of tolerances we work to we needed a torque sensor that didn’t add any extra drag to the whole seal mechanism, so we were delighted to discover Sensor Technology’s non-contact TorqSense,” says Jeff.

@sensortech  #PAuto #Torque #Vacuum